1. Field of the Invention
This invention is in the field of hand tools of the type commonly referred to as "nibbling" tools which operate to cut a small chip out of the material upon each downward stroke of the cutting edge. The cutting strokes can be made in rapid succession and quite easily, with sufficient leverage being available to allow cutting of relatively heavy materials. The arrangement of the cutting edge and the geometry of the cutting element are such that the cutting direction can be varied incrementally between cuts so as to provide an almost limitless geometry of cuts.
2. Description of the Prior Art
The only prior art with which the applicant is familiar is Adel U.S. Pat. No. 2,542,103 directed to a nibbling tool. This device included an elongated frame having spaced walls, and a stationary cutting edge extending between the walls. A cutter bar was mounted in the frame between the walls for guided longitudinal reciprocation. A movable cutting edge was provided for cooperating with the stationary cutting edge during the nibbling stroke. A lever was pivotally mounted on the frame and had a portion disposed between the walls of the frame and directly engaged with the part on the cutter for starting the nibbling stroke, together with a spring for urging the cutter bar during the return stroke back to its normal position.
Tools apparently produced under the Adel patent were on the market but met with limited success. Such tools were rather limited in their ability to cut different sized apertures and they were sometimes presented with the problem of clogging of the tool upon successive cuts.